This invention is an improvement over Hoey, U.S. Pat. No. 3,618,754, issued Nov. 9, 1971, which is also the closest prior art of which the applicants of the present invention are aware. Hoey discloses a continuous fabric web which is conveyed in a fully stretched condition and which is adhesivecoated in such stretched condition using high heat calender rolls. Hoey's method causes two problems. First, by applying the adhesive to a fully stretched fabric, the bandaging material has poor breathability when used. That is, in use, the bandaging material is stretched and the adhesive layer is thick and uniform in depth, preventing air passage through the adhesive layer. Second, by heating the fully stretched elastomeric warp yarns to between 240.degree. and 240.degree. F., the stretch warp yarns lose a great deal of their power of recovery and a great deal of their elasticity.
This is precisely the opposite way in which applicants' bandaging material is produced, i.e. applicants' fabric is first steamed and is then coated with an adhesive layer, both steps occurring while the fabric is being conveyed in a fully relaxed condition. Applicants avoid using high heat throughout their process.
Because of this difference in the methods by which Hoey's bandaging material and applicants' bandaging material are produced, the resulting materials have different physical characteristics. Hoey does not initially steam his fabric whereas applicants do steam their fabric. This steaming step exfoliates and spreads the interwoven filling and warp yarns of applicants' fabric and also expands and loosens non-stretch yarns thereby facilitating a fuller retraction of applicants' stretch warp yarns. As a result, applicants' bandaging material strongly and repeatedly recovers to its original relaxed length after being stretched, whereas the Hoey bandaging material has a weaker snap-back and has reduced elasticity especially after an extended period of full stretch.
Furthermore, applicants' fabric preferably receives an acrylic polymer coating which improves the tearability of applicants' bandaging material and which inhibits fraying at the edges of the material. Hoey's material does not receive such a coating.
For all of the foregoing reasons, applicants' bandaging material is an improvement over the Hoey material and is a decided advance in the art.